This invention relates to radio frequency communication systems and vehicle warning systems and, more particularly, to an electronic system utilizing radio transmission to warn, direct, and inform vehicle operators by use of visible and audible information, or both, for general traffic control and warning purposes.
The crowding of highways, the need for conservation of fuel, and increasing concern for safety, have emphasized the importance and desirability of rigidly enforcing the observation of vehicle speed limits with consequent imposition of a national maximum speed limit. However, the limiting of speed is not in and of itself a solution to the need for warning an unwary driver or one heedlessly bent on maintaining the maximum speed limit.
There has been a long-felt need to warn drivers to observe reduced speed limits in dangerous situations or in locations where there are operations of vehicles in excess of a certain speed constitutes a clear and present danger to themselves, occupants of other vehicles, and pedestrians. In the event of emergency conditions or road conditions of an abnormal or otherwise unsafe character, there is a need to alert drivers, as by indicating to them the existence of a situation requiring the reduction of speed or other extraordinary action.
As our society has changed from a primarily rural nature to a more or less urban nature, and as population and density of automobiles on our highways have increased, there has grown up a forest of signs along our highways. There are signs to the right, signs to the left, signs overhead, and signs on the pavement. In many situations, one is distracted by the variety and plethora of advertisements and directional signs, as well as those which identify various routes or which caution against parking, give various information relative to the location of facilities and services, and others. All of these detract from a driver's ability to concentrate on warning signs. Thus, to an extent greater than ever before, drivers frequently ignore warning signals and particularly those calling attention to unusual or dangerous conditions.
Even if drivers were more wary than they are and heeded the admonitions of signs pointing out dangers and the need to take precautions, as for example, the reduction of speed or changing of lanes to avoid a dangerous condition, it must be recognized that signs have no "voice" or other capability to warn of severe weather conditions such as low visibility and lack an intrusive nature which commands a driver's attention when he is confused, fatigued, or is momentarily distracted by something within or without his vehicle such as, for example, when he is tuning his radio, attending to various amusement appliances such as tape players or the like, lighting smoking material, talking with passengers, or is looking at a map, etc. Further, a driver may, out of habit, tend to drive in a haphazard and careless manner which overlooks safety. The attention of such drivers is not commanded by signs.
Accident stastics reveal that the imposition of speed limits has not overcomes these long-standing problems and the multiplicity and financial magnitude of claims against automobility liability insurers evidence a continuing and most compelling need for finding additional ways to prevent vehicle accidents that result in injury, loss of life and property.
What is needed are improved ways of providing to a driver aural and/or visual warnings of a nature which will command a driver's attention so that the driver may be alerted to dangerous conditions, the need to take evasive action, reduce speed, pull over, or the like. Because of the crowding of highways and ever present wailing of sirens and existence of various sources of external flashing lights, drivers often fail to heed such signals. Moreover, the shattering effect on the nerves of a motorist produced by a screaming siren or loud air horns of a fire engine as the same approach a vehicles has sometimes caused drivers to panic and act in an irrational or dangerous way. There have been heretofore a picking up by means of a microphone, amplifying and then reproducing within a vehicle sounds of a siren, horn or other allowed noise generated externally of the vehicle. But, such systems do no more than increase the effective loudness of such screaming sirens or other loud noises. Thus, such systems fall far short of representing a solution of the problems hereinabove discussed.
It would be most desirable if police officers or the authorized officers of other emergency vehicles such as fire engines, ambulances or rescue equipment, could speak directly to drivers or in other ways cause them to receive visual or aural warning signals within their vehicles.
It has been proposed in Bost U.S. Pat. No. 3,233,217 to provide a vehicle signal device having a plurality of warning lights which are adapted to be actuated by a transmitter which is either fixed, or is carried by an ambulance, a fire truck, police car, or the like. The device is intended to be mounted within a vehicle and has several lights which may signal various conditions dependent upon the tone with which the transmitted signal is coded. However, such system provides no audible signalling of the driver, much less a capability of direct voice transmission to a driver from a police vehicle, and the provision of simple warning lights, as proposed by this reference, does not solve the foregoing problems.
An electronic warning system for vehicles is contemplated by Gelushia et al U.S. Pat. No. 3,532,986 wherein there is disclosed a warning system for vehicles in which each vehicle in a similar mode of travel would be similarly equipped with a system including a combined transmitter-receiver. The transmitter is provided with an oscillator which modulates the transmission frequency so that the receiver of another vehicle can detect an audio signal, including possible voice transmissions, and provide the same to a loud speaker within the receiving vehicle as an alarm. But, like the Bost disclosure, this patent comtemplates a system tuned to a specific frequency. Thus, to transmit any usable information from another vehicle to a receiving vehicle, the transmitting vehicle would have to be tuned to a specific frequency. In addition, the Gelushia et al system is not capable of discriminating between various types of different signals which might represent different conditions as to which it is desired to give warning, but instead is designed to receive all transmissions on the specific frequency to which it is pretuned.
A more sophisticated approach is the emergency communication system disclosed by Hemmer et al U.S. Pat. No. 3,986,119 wherein vehicles equipped with portable communicators may initiate communication with a radio relay station which then establishes a further communications link with a terminal station. The latter sends back signals to a remote receiver-transmitter which in turn signals the portable transmitter-receiver carried by a vehicle that a message has been received. Such system is not intended for receiving transmissions from a police vehicle, nor does the system lend itself for voice transmission between the portable units carried by vehicles and police radio-transmission equipment.
Generally relevant to the problem of providing the transmission of warning systems of a vehicle in distress is Trumble U.S. Pat. No. 3,461,423 which contemplates not only a circuit adapted for modulating the transmitted frequency with one of various tones in accordance with a type of condition to be signalled, but also the provision of a commercially activated switch which closes in response to a collison or the like to initiate emergency transmission. But, like the previous references, such transmission is at a specific frequency different from that utilized by police and does not provide for transmission of voice messages from a police vehicle to another vehicle.
These and numerous other patents represent the diverse and fragmented efforts of many others to provide partial solutions to the needs which are discussed hereinabove. Yet, taken individually and collectively, they fail to represent a comprehensive solution to such problems. Moreover, these efforts of the prior art have generally failed to make use of existing radio equipment, such as that which police vehicles are presently equipped, for the purpose of providing, within civilian vehicles, audio tones of a useful warning character, direct or recorded voice messages from police vehicles or other transmitters useful for providing warning messages, as well as visible indications and combinations of audible and visible signalling.
It is an object of the present invention to provide a comprehensive system utilizing radio transmission on police band frequencies for providing to drivers, within civilian vehicles, visible and audible warnings or other messages for traffic control purposes transmitted from positions remote from such vehicles.
A further object of the invention is to provide such a system with the capability of delivering voice transmission to such drivers of civilian vehicles from police or other authorities transmitting within the police band.
Yet another object of the invention is to provide such a system allowing direct voice communications to drivers of such civilian vehicles by police or other authorities or governmental agencies without requiring resort to the use of sirens, horns, or flashing lights on police or other governmental vehicles to alert such drivers.
Another object of the invention is the provision of a system of the character stated which provides visible and audible warnings to drivers within civilian vehicles only upon the selective transmission of pulse coded signals from authorized equipment.
Another object of the invention is the provision of such a system wherein warnings may be transmitted to such civilian vehicles on any frequency within a given police band.
A related object of the invention is the provision of such a system which is selective to such signals transmitted at any frequency within a police band.
A further object of the invention is the provision of a system of the character stated wherein visible or audible warnings, or both, may be transmittd automatically by radio transmission automatically in response to a collision involving such vehicle.
Yet another object of the invention is the provision of a system of the character stated adapted for providing visible and audible warnings within such civilian vehicles in response to dangerous conditions which are present in advance of a civilian vehicle as it travels along a highway.
Among further objects of the invention may be noted the provision of such a system which is constructed of proven, inexpensive, and reliable electronic circuitry; which is assembled with the use of a minimum of parts and is conducive to extremely economical mass-production assembly; and which is reliable and long-lasting in use.
Other objects will be in part apparent and in part pointed out hereinbelow.